S. Al-Ashhab, Nullspace of compound magic squares, International Journal of Open Problems in Mathematics and Computer Science
In this paper we consider special compound 4n? 4n and 6n? 6n
magic squares. We determine a 2n?3 (res. 3n?5 ) dimensional
subspace of the nullspace of the 4n? 4n (res. 6n? 6n ) squares. All
vectors in the subspaces possess the property that the sum of all
entries of each vector equals zero.
